src/mem/cache/miss/mshr_queue.cc

   1 /*
   2  * Copyright (c) 2003-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Erik Hallnor
  29  */
  30
  31 /** @file
  32  * Definition of the MSHRQueue.
  33  */
  34
  35 #include "mem/cache/miss/mshr_queue.hh"
  36 #include "sim/eventq.hh"
  37
  38 using namespace std;
  39
  40 MSHRQueue::MSHRQueue(int num_mshrs, int reserve)
  41     : numMSHRs(num_mshrs + reserve - 1), numReserve(reserve)
  42 {
  43     allocated = 0;
  44     inServiceMSHRs = 0;
  45     allocatedTargets = 0;
  46     registers = new MSHR[numMSHRs];
  47     for (int i = 0; i < numMSHRs; ++i) {
  48         freeList.push_back(&registers[i]);
  49     }
  50 }
  51
  52 MSHRQueue::~MSHRQueue()
  53 {
  54     delete [] registers;
  55 }
  56
  57 MSHR*
  58 MSHRQueue::findMatch(Addr addr) const
  59 {
  60     MSHR::ConstIterator i = allocatedList.begin();
  61     MSHR::ConstIterator end = allocatedList.end();
  62     for (; i != end; ++i) {
  63         MSHR *mshr = *i;
  64         if (mshr->addr == addr) {
  65             return mshr;
  66         }
  67     }
  68     return NULL;
  69 }
  70
  71 bool
  72 MSHRQueue::findMatches(Addr addr, vector<MSHR*>& matches) const
  73 {
  74     // Need an empty vector
  75     assert(matches.empty());
  76     bool retval = false;
  77     MSHR::ConstIterator i = allocatedList.begin();
  78     MSHR::ConstIterator end = allocatedList.end();
  79     for (; i != end; ++i) {
  80         MSHR *mshr = *i;
  81         if (mshr->addr == addr) {
  82             retval = true;
  83             matches.push_back(mshr);
  84         }
  85     }
  86     return retval;
  87
  88 }
  89
  90 MSHR*
  91 MSHRQueue::findPending(Packet * &pkt) const
  92 {
  93     MSHR::ConstIterator i = pendingList.begin();
  94     MSHR::ConstIterator end = pendingList.end();
  95     for (; i != end; ++i) {
  96         MSHR *mshr = *i;
  97         if (mshr->addr < pkt->getAddr()) {
  98             if (mshr->addr + mshr->pkt->getSize() > pkt->getAddr()) {
  99                 return mshr;
 100             }
 101         } else {
 102             if (pkt->getAddr() + pkt->getSize() > mshr->addr) {
 103                 return mshr;
 104             }
 105         }
 106
 107         //need to check destination address for copies.
 108         //TEMP NOT DOING COPIES
 109 #if 0
 110         if (mshr->pkt->cmd == Copy) {
 111             Addr dest = mshr->pkt->dest;
 112             if (dest < pkt->addr) {
 113                 if (dest + mshr->pkt->size > pkt->addr) {
 114                     return mshr;
 115                 }
 116             } else {
 117                 if (pkt->addr + pkt->size > dest) {
 118                     return mshr;
 119                 }
 120             }
 121         }
 122 #endif
 123     }
 124     return NULL;
 125 }
 126
 127 MSHR*
 128 MSHRQueue::allocate(Packet * &pkt, int size)
 129 {
 130     Addr aligned_addr = pkt->getAddr() & ~((Addr)size - 1);
 131     assert(!freeList.empty());
 132     MSHR *mshr = freeList.front();
 133     assert(mshr->getNumTargets() == 0);
 134     freeList.pop_front();
 135
 136     if (!pkt->needsResponse()) {
 137         mshr->allocateAsBuffer(pkt);
 138     } else {
 139         assert(size !=0);
 140         mshr->allocate(pkt->cmd, aligned_addr, size, pkt);
 141         allocatedTargets += 1;
 142     }
 143     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 144     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 145
 146     allocated += 1;
 147     return mshr;
 148 }
 149
 150 MSHR*
 151 MSHRQueue::allocateFetch(Addr addr, int size, Packet * &target)
 152 {
 153     MSHR *mshr = freeList.front();
 154     assert(mshr->getNumTargets() == 0);
 155     freeList.pop_front();
 156     mshr->allocate(Packet::ReadReq, addr, size, target);
 157     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 158     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 159
 160     allocated += 1;
 161     return mshr;
 162 }
 163
 164 MSHR*
 165 MSHRQueue::allocateTargetList(Addr addr, int size)
 166 {
 167     MSHR *mshr = freeList.front();
 168     assert(mshr->getNumTargets() == 0);
 169     freeList.pop_front();
 170     Packet * dummy;
 171     mshr->allocate(Packet::ReadReq, addr, size, dummy);
 172     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 173     mshr->inService = true;
 174     ++inServiceMSHRs;
 175     ++allocated;
 176     return mshr;
 177 }
 178
 179
 180 void
 181 MSHRQueue::deallocate(MSHR* mshr)
 182 {
 183     deallocateOne(mshr);
 184 }
 185
 186 MSHR::Iterator
 187 MSHRQueue::deallocateOne(MSHR* mshr)
 188 {
 189     MSHR::Iterator retval = allocatedList.erase(mshr->allocIter);
 190     freeList.push_front(mshr);
 191     allocated--;
 192     allocatedTargets -= mshr->getNumTargets();
 193     if (mshr->inService) {
 194         inServiceMSHRs--;
 195     } else {
 196         pendingList.erase(mshr->readyIter);
 197     }
 198     mshr->deallocate();
 199     return retval;
 200 }
 201
 202 void
 203 MSHRQueue::moveToFront(MSHR *mshr)
 204 {
 205     if (!mshr->inService) {
 206         assert(mshr == *(mshr->readyIter));
 207         pendingList.erase(mshr->readyIter);
 208         mshr->readyIter = pendingList.insert(pendingList.begin(), mshr);
 209     }
 210 }
 211
 212 void
 213 MSHRQueue::markInService(MSHR* mshr)
 214 {
 215     //assert(mshr == pendingList.front());
 216     if (!(mshr->pkt->needsResponse() || mshr->pkt->cmd == Packet::UpgradeReq)) {
 217         assert(mshr->getNumTargets() == 0);
 218         if ((mshr->pkt->flags & SATISFIED) && (mshr->pkt->cmd == Packet::Writeback)) {
 219             //Writeback hit, so delete it
 220             //otherwise the consumer will delete it
 221             delete mshr->pkt->req;
 222         }
 223         deallocate(mshr);
 224         return;
 225     }
 226     mshr->inService = true;
 227     pendingList.erase(mshr->readyIter);
 228     //mshr->readyIter = NULL;
 229     inServiceMSHRs += 1;
 230     //pendingList.pop_front();
 231 }
 232
 233 void
 234 MSHRQueue::markPending(MSHR* mshr, Packet::Command cmd)
 235 {
 236     //assert(mshr->readyIter == NULL);
 237     mshr->pkt->cmd = cmd;
 238     mshr->pkt->flags &= ~SATISFIED;
 239     mshr->inService = false;
 240     --inServiceMSHRs;
 241     /**
 242      * @ todo might want to add rerequests to front of pending list for
 243      * performance.
 244      */
 245     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 246 }
 247
 248 void
 249 MSHRQueue::squash(int threadNum)
 250 {
 251     MSHR::Iterator i = allocatedList.begin();
 252     MSHR::Iterator end = allocatedList.end();
 253     for (; i != end;) {
 254         MSHR *mshr = *i;
 255         if (mshr->threadNum == threadNum) {
 256             while (mshr->hasTargets()) {
 257                 Packet * target = mshr->getTarget();
 258                 mshr->popTarget();
 259
 260                 assert(0/*target->req->getThreadNum()*/ == threadNum);
 261                 target = NULL;
 262             }
 263             assert(!mshr->hasTargets());
 264             assert(mshr->ntargets==0);
 265             if (!mshr->inService) {
 266                 i = deallocateOne(mshr);
 267             } else {
 268                 //mshr->pkt->flags &= ~CACHE_LINE_FILL;
 269                 ++i;
 270             }
 271         } else {
 272             ++i;
 273         }
 274     }
 275 }